At the end of last week’s episode of NCIS, Gibbs (Mark Harmon) took a picture of the team’s target, Harper Dearing (Richard Schiff), and stuck it over the picture of Osama bin Laden that hangs on the Most Wanted wall inside NCIS HQ. The message: Dearing is going down.

But first it’s going to take the team into a high-stakes fight against an incredibly dangerous adversary, says EP Gary Glasberg. “This arc is something that we’ve been talking about for a while,” he says of the terrorist plot. “And I think people are going to be, not only surprised, but really entertained by how it unfolds… Anytime that the team gets to work mode as a cohesive unit, people enjoy that and respond to it. That’s definitely the case in terms of this storyline.”

And if you think you know the full story: stay tuned. The upcoming final episodes will be more than your average cat-and-mouse game. As the story unfolds, he says, “there are so many elements to it that connect directly to Gibbs that explain a lot of the motivation on Harper Dearing’s part [and] that will connect to Jamie Lee Curtis and even connect to Scott Wolf’s character…A lot of planning has gone into it.”

But as NCIS deals with a very intense threat, there’s also a bit of joy to be found, as their friend and colleague Jimmy Palmer prepares to wed in Florida. This storyline will diffuse some of the tension caused by the larger arc. “It’s a really fascinating juxtaposition of this Palmer moment with the manhunt that’s going on for Harper Dearing,” says Glasberg. “[Co-executive producer] Steve Binder came up with a really clever way of jumping back and forth between the two and weaving the two together. I think it worked really nicely and people are going to get the lighter moments that only NCIS could pull off. At the same time, we don’t miss a beat in terms of keeping the hunt going as well.”

As expected, it all wraps up with a “true” cliffhanger. Considering Gibbs’ longtime friend Mike Franks (Muse Watson) was shockingly killed by Jonas Cobb at the end of last season, Glasberg knows the expectations are high. “People are going to be surprised by what happens. There’s no doubt about that,” he says. “There’s going to be a ripple effect that goes through NCIS.”